[SS-VehDev] Re: casing

[Lakestake Rocketry]

Hi Roman,

Do you want to take up this challenge with me? I think we can
make better tube for less.

Matt C

P.S. I am making a bunch of 10" CF tube now for a scale M100
(russian sounding rocket of course!) As I am tooling up I can run
out a few dozen feet of SS2S tube while I am at it.

I am looking for your confirmation that this is practical as I have
not finalized my plans for the M100. I would also enjoy you
as a collaborator on the team building the airframe. Let me
know what you think.

Are you visiting LA any time soon?

On 9/29/05, Lakestake Rocketry <lakestake at gmail.com> wrote:
>
> Hi Roman,
>
> Do you want to go in on this with me? I think we can
> make better tube for less.
>
> Matt
>
> ---------- Forwarded message ----------
> From: william colburn <space1space at sbcglobal.net>
> Date: Sep 29, 2005 1:08 PM
> Subject: casing
> To: "Robert H. Krech" <krech at psicorp.com>, william colburn <
> space1space at sbcglobal.net>, richnakka at rogers.com, Lakestake Rocketry <
> lakestake at gmail.com>, roman.lev at aero.cz, "David (Beltsville) Smith" <
> david.smith2 at perkinelmer.com>
>
> At this point, I need some additional help in locating
> our casing material. I should be getting a very
> belated quote on the composite tubing.
>
> The composite tubing is made in standard inch ID's. So
> the closest to our size is 10 inch ID. This makes the
> casing 10.375 OD. It is certainly workable, but not
> compatible with the nozzle which has already gone into
> scheduling. That was designed for a .06 wall with a
> 10.00 inch OD casing, or titanium.
> The target cost for the composite is $65 a foot.
> Probably doable with the current membership.
> Advantages are it will be solid white in color, very
> easily machined, drilled, good rigidity due to
> additional wall thickness. Drawbacks are: diameter is
> off our spec, attachments require about .5 Diameters,
> somewhat more thermally sensitive.
>
> The tubing they are quoting is NOT carbon composite.
>
> Now we could also do a carbon composite layup. The
> HAH-203 (see Hybriddyne.com <http://Hybriddyne.com>) is partially carbon
> composite, hand layup. With the shrink-wrap technique,
> very good results are gotten with no autoclave or
> bagging. Possible within our group.
>
>
> We can certainly adapt to the composite if necessary.
>
> The problem with the Titanium tubing is the cost. We
> need a few 10K's in donations before we can order.
>
> In seeking tubing, the material yield strength must be
> above this value: 687,000 x material density in
> lbm/in^3 = yield strength psi. This will preserve our
> mass fraction. Use this equation to estimate wall
> thickness:
>
> wall thickness = .180 x (41,000)/ material yield psi)
>
> So 4130 at a high temper of 194 KSI requires a wall
> thickness of .038 inch. Titanium at 123 ksi gives a
> wall of .06 inch.
>
> So this is an appeal to research possible casing
> sources, materials, pricing, donations.
>
> Rich, this is more properly in your domain, but I got
> involved due to some tubing sources I had so I am
> putting this out to the veh dev group.
>
> BC
>
>
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